What name is given to the 2007–2009 worldwide collapse that began with the U.S. subprime mortgage crisis?

The 2007–2009 worldwide collapse that began with the U.S. subprime mortgage crisis is known as the global financial crisis.

U.S. house prices had risen for years while lenders extended large numbers of mortgages to borrowers with weaker credit histories. These loans were packaged into mortgage-backed securities and other complex products, distributing housing-market risk throughout the financial system. When house prices fell and defaults increased, the value of many securities became uncertain.

The crisis intensified in September 2008, when Lehman Brothers filed for bankruptcy. Credit markets froze, banks became reluctant to lend, and stock markets plunged around the world. Governments and central banks responded with emergency lending, bank rescues, fiscal stimulus, and sharp interest-rate cuts.

The resulting recession was the deepest global downturn since the Great Depression. In the United States, the Troubled Asset Relief Program authorized up to $700 billion to stabilize the financial system. New regulations, including the Dodd–Frank Act, followed in an effort to reduce systemic risk.